About CPA bidding

CPA (pay-per-conversion) is a way to pay only when a user converts. CPA is a Smart Bidding strategy that automatically adjusts your bid to help you maximize conversions. You pay a percent of booking value that you set.

This bid strategy is only available with Hotel campaigns and isn't supported for legacy account bids. This section describes the CPA bid strategy in the following topics:

CPA helps you achieve a predictable cost per conversion. This cost is a percentage of booking value that you set in the Hotel Ads Center. The CPA should represent how much revenue you're willing to spend on Hotel Ads for each dollar that you earn from bookings from your Hotel Ads.

Before you begin

While optional, these parameters also help Google optimize your performance:

hct_checkin_date

hct_checkout_date

hct_partner_hotel_id

hct_total_price

Notes:

The value of hct_base_price is used to compute your CPA cost for a particular conversion. If this value is missing from a conversion event, then Google falls back to using hct_total_price as the basis for computing your cost. If neither is provided, Google will interpret that conversion as having zero value.

There is no minimum number of conversions required to enable a campaign using CPA.

How CPA works

The CPA bidding strategy predicts future conversions and associated values by using your reported conversion values, which you assign through conversion tracking. Then CPA sets an optimal cost-per-click (CPC) bid while trying to maximize total conversions at the cost-per-conversion equal to your target.

To help improve your performance, the CPA bidding strategy adjusts bids using auction-time details such as the customer's device type and location, the Google site where the Hotel Ad appears, geographic location, itinerary, and hotel price.

The average cost-per-click will vary, but regardless of the number of ad clicks, you only pay if a conversion happens.

Note: CPA is meant to help maximize your ads' reach, and because you only pay when users convert, costs from this bid strategy will not count towards your account's daily budget.

Choose the right CPA bid

To find the right CPA bid, determine what distribution margin you want to spend for your bookings.

For example, if your goal is to spend an average of 12% of booking value and maximize your booking revenue, and you have a cancellation rate of 10%, then your CPA should be 10.8%.

If you decrease your CPA, your bid in the auction will decrease and can result in less bookings. Similarly, if you increase your CPA, your bid in the auction will increase and can result in more bookings. Keep in mind this depends on the auction, and booking volume changes aren't guaranteed with CPA changes.

Conversion metrics

Conversion metrics such as "Conversions" and "Average Booking Value" can be updated one or more days after a click occurs depending on when an individual user converts and your account's attribution window (the number of days after the customer clicked that we'll attribute a conversion to a click). This means that the cost for a campaign using a CPA bid strategy can also change one or more days after a click.

This section lists some best practices when setting up and using the CPA bidding strategy.

Setting up CPA

To get the best performance with CPA, your campaign should have at least 20 conversions per day. If your campaigns don't have this many conversions per day, consider merging some campaigns together when using CPA.

Allow the campaign to accumulate traffic for at least 7 days before evaluating performance and making changes.

Don't change your CPA bid more than once every few weeks. This gives you time to account for any conversion delays and give the CPA autobidder strategy time to adjust.

Ensure conversion tracking is well implemented on all points of sale and all devices. Outages in conversion tracking (complete or partial) can significantly impact your performance and volume.

Tune and evaluate

The more data Hotel Ads has, the more it can optimize CPA bids.

Keep in mind that changes in ad performance are natural, and you may need to use the CPA bid strategy for some time to understand how it affects your campaign's performance.

Don't make large changes to a campaign while running the CPA bid strategy. (For example, don't pause all active hotel IDs and replace them with new ones.)

Don't remove your conversion tracking code from your website or move it to a different location while running the CPA bid strategy. These kinds of changes can result in significant changes in which clicks lead to reported conversions. If you do change your conversion tracking code, the CPA bid strategy might need several weeks to adjust to these changes.

Compare your clicks and conversion rate before and after using the CPA bid strategy to gauge its impact on your campaign.

When using the CPA bidding strategy, Hotel Ads sets optimal cost-per-click (CPC) bids for partners' hotels to help maximize booking value at the specified cost-per-conversion, which is a percent of booking value you set.

Conversion metrics (counts, values, cost, and ROAS) listed in the performance dashboard, and in performance reports, are always associated with the date of the click that led to the conversion, because of delayed conversions.

CPA costs are billed as of the date of the conversion. This means that you may see a slightly different total cost for your CPA campaigns in the Hotel Ads Center and your monthly invoice. For example, if a click happens on the last day of this month, and the user converts on the first day of the next month, you would only be charged for that click on the invoice at the end of the next month. However, your performance metrics for the last day of this month (the day of the click) would be updated to reflect that conversion and CPA cost.